Mahmoudi Gahrouei Masoumeh, Vlastos Nikiphoros, D'Souza Ransell, Odogwu Emmanuel C, de Sousa Oliveira Laura
Department of Chemistry, University of Wyoming, 1000 E. University Ave., Laramie, Wyoming 82071, United States.
Department of Mechanical and Materials Engineering, University of Turku, Turku 20014, Finland.
J Chem Theory Comput. 2024 May 14;20(9):3976-3992. doi: 10.1021/acs.jctc.3c01405. Epub 2024 May 6.
Recent studies have shown that metal-organic frameworks (MOFs) have potential as thermoelectric materials, and the topic has received increasing attention. The main motivation for this project is to further our knowledge of thermoelectric properties in MOFs and find which available self-consistent-charge density functional tight binding (SCC-DFTB) method can best predict (at least trends in) the electronic properties of MOFs at a lower computational cost than standard density functional theory (DFT). In this work, the electronic properties of monolayer, serrated, AA-stacked, and/or AB-stacked ZnCO, CdCO, Zn-NH-MOF─for which no previous calculations of thermoelectric performance exist─and Ni(HITP) MOFs are modeled with DFT-PBE, DFT-HSE06, GFN1-xTB, GFN2-xTB, and DFTB-3ob/mio. The band structures, density of states, and their relative orbital contributions, as well as the electrical conductivity, Seebeck coefficient, and power factor, are compared across methods and geometries. Our results suggest that GFN-xTB is adequate to predict the MOFs' band structure shape and density of states but not band gap. Our calculations further indicate that ZnCO, CdCO, and Zn-NH-MOF have higher power factor values than Ni(HITP), one of the highest performing synthesized MOFs, and are therefore promising for thermoelectric applications.
最近的研究表明，金属有机框架（MOF）作为热电材料具有潜力，这一话题已受到越来越多的关注。该项目的主要动机是进一步了解MOF的热电性能，并找出哪种可用的自洽电荷密度泛函紧束缚（SCC-DFTB）方法能够以低于标准密度泛函理论（DFT）的计算成本，最佳地预测（至少是趋势）MOF的电子性质。在这项工作中，使用DFT-PBE、DFT-HSE06、GFN1-xTB、GFN2-xTB和DFTB-3ob/mio对单层、锯齿状、AA堆叠和/或AB堆叠的ZnCO、CdCO、Zn-NH-MOF（此前没有对其热电性能进行过计算）以及Ni(HITP) MOF的电子性质进行建模。对不同方法和几何结构的能带结构、态密度及其相对轨道贡献，以及电导率、塞贝克系数和功率因数进行了比较。我们的结果表明，GFN-xTB足以预测MOF的能带结构形状和态密度，但无法预测带隙。我们的计算进一步表明，ZnCO、CdCO和Zn-NH-MOF的功率因数值高于Ni(HITP)（性能最佳的合成MOF之一），因此在热电应用方面具有潜力。
